This is incorrect, Braben and Brookes have both said they will support all VR.
However currently because Vive have a stable and market ready driver and SDK it is easier to integrate into the game and this why dev is focusisng on that.
Occulus broke compatibility between 0.6 and 0.8 sdk, and said that they may break it again with the 1.0 sdk release
Since the Cobra engine used by ED writted by frontier has to manually make these changes each time shit is broken its mush harder for them to agree to do a whole dev cycle until there is a stable release and future releases are backward compatibile ..
unlike other games that can pick up the changes more quickly like UE4 based games because occulus thmselves write a plugin direct for that engine.
Project cars is another one that is in the same boat as ED
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